Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
thanh vi » hanh vi, thanh va, thanh ve
dua tren » dung tren
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang xa hoi. lieu va cau truc va thanh vi ((((cua tre) or (dua tren))) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. lieu va cau truc va thanh vi ((((cua tre) OR (dua tren))) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. lieu va cau truc va thanh vi ((((cua tre) or (dua tren))) or (cua viet))*.